It was confirmed yesterday that Chief Superintendent Adrian Roberts has been temporarily promoted to the rank of Assistant Chief Constable.

Mr Pickard moved to calm public concern over the future of the force, and vowed that officers will continue to do their best to police the streets of Teesside.

He said: “This is a difficult period for everyone involved with the force, but I know there is total commitment at every level and from every officer and member of staff, including our partnership staff, to Putting People First and continuing with our day-to-day duties of serving and protecting our communities.

“Our focus has to be on business as usual - we will not let matters which in reality are largely outside the control of the force and the authority divert us from that task, and nor should it divert attention from the massive progress we have achieved in recent years in making Cleveland Police one of the best and most effective forces in the country.”

Her Majesty’s Inspectorate of Constabulary began investigations in August last year, before handing the case over to Warwickshire Police in April.

The force made the investigation public in May, and announced it was being carried out with support from officers from North Yorkshire.

It was announced that the probe centred on people with “current or past associations” with Cleveland Police Authority.

Mr Price, Mr Bonnard, and the force’s former legal advisor Caroline Llewellyn, have been bailed until October.

Shortly after the Warwickshire Police investigation was announced, Councillor Dave McLuckie stepped down as chairman of the police authority. He revealed that he believed he was being investigated, but denied any wrongdoing.

His replacement Peter Race said today that the public will continue to receive the “best possible service”. The pledge comes after Cleveland Police Federation said some frontline officers had received abuse from the public following the arrests of the senior officers.

Mr Race added: “I am sure that it has been a tough time for every officer and member of staff but I know they have the full support of the entire police authority - and I believe the public - in carrying on with their duties.

“Quite rightly there is a concern that the investigations taking place should be concluded as quickly as possible in the interests of everyone concerned and that is what we are determined to press for.”